ENT · Acute Rhinosinusitis
The facts most likely to be tested
Acute bacterial rhinosinusitis is primarily a clinical diagnosis characterized by symptoms lasting greater than 10 days without improvement.
The most common bacterial pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
Double sickening (initial improvement followed by worsening symptoms) is a highly specific indicator of secondary bacterial infection.
First-line empiric antibiotic therapy for acute bacterial rhinosinusitis is amoxicillin-clavulanate.
Viral rhinosinusitis is the most common etiology and should be managed with supportive care including intranasal saline and analgesics.
Imaging, such as CT of the sinuses, is reserved for patients with orbital or intracranial complications or suspected fungal disease.
Patients with a penicillin allergy should be treated with doxycycline or a respiratory fluoroquinolone like levofloxacin.
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A 34-year-old male presents with 12 days of purulent nasal discharge, maxillary tooth pain, and facial pressure. He initially felt better after a mild cold last week, but his symptoms have recently worsened with a recurrent fever and increased congestion. Physical exam reveals tenderness to palpation over the maxillary sinuses. He has no history of recent antibiotic use and no known drug allergies.
What is the most appropriate next step in management?
Amoxicillin-clavulanate
The patient exhibits the classic 'double sickening' pattern and symptoms lasting >10 days, meeting the criteria for acute bacterial rhinosinusitis, which requires antibiotic therapy.
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Etiology / Epidemiology
Most cases are viral following URI; bacterial superinfection occurs in <2% of cases. Streptococcus pneumoniae is the most common bacterial pathogen.
Clinical Manifestations
Purulent nasal discharge, maxillary tooth pain, and sinus pressure worsening with leaning forward. Symptoms lasting >10 days suggest bacterial etiology.
Diagnosis
Clinical diagnosis; CT scan of sinuses is the gold standard if complications are suspected. Avoid imaging for uncomplicated cases.
Treatment
Amoxicillin-clavulanate is the first-line antibiotic. Avoid fluoroquinolones as first-line therapy due to side effect profile.
Prognosis
Most resolve spontaneously. Orbital cellulitis and intracranial abscess are rare but life-threatening complications.
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Epidemiology & Etiology
Acute rhinosinusitis is primarily a complication of the common cold. Bacterial causes are dominated by S. pneumoniae, H. influenzae, and M. catarrhalis. Smoking and allergic rhinitis are significant risk factors for impaired mucociliary clearance.
Pertinent Anatomy
The ostia of the sinuses are narrow channels prone to obstruction by mucosal edema. The maxillary sinus is the most commonly affected due to its dependent drainage pathway.
Pathophysiology
Viral infection causes mucosal inflammation, leading to ostial obstruction and impaired mucociliary clearance. This creates a stagnant environment favoring bacterial overgrowth. Persistent inflammation results in sinusitis and localized pressure.
Clinical Manifestations
Patients present with purulent nasal discharge, facial pain, and hyposmia. Maxillary tooth pain is a classic board finding. Red flags include high fever, periorbital edema, or altered mental status, suggesting orbital cellulitis or cavernous sinus thrombosis.
Diagnosis
Diagnosis is strictly clinical based on symptom duration. CT scan of the sinuses is the gold standard for surgical planning or suspected complications. Imaging is not indicated for uncomplicated cases to avoid unnecessary radiation.
Treatment
Symptomatic relief with intranasal steroids and saline irrigation is first-line. If bacterial etiology is confirmed, Amoxicillin-clavulanate is the drug of choice. Fluoroquinolones are reserved for patients with severe penicillin allergies due to the risk of tendon rupture and QT prolongation.
Prognosis
Most cases resolve within 2 weeks. Monitor for orbital cellulitis or meningitis if symptoms worsen after initial improvement. Persistent symptoms beyond 12 weeks define chronic sinusitis.
Differential Diagnosis
Allergic rhinitis: associated with sneezing and itchy, watery eyes
Viral URI: symptoms typically resolve within 7-10 days
Dental abscess: localized pain restricted to the tooth/gum line
Migraine: unilateral throbbing pain without nasal discharge
Foreign body: unilateral foul-smelling discharge, common in children